Oil Spill Near Unesco World Heritage Site in South Pacific Is Spreading

SYDNEY, Australia — An oil spill from a cargo ship that ran aground near a World Heritage site in the South Pacific is spreading, alarming environmentalists and government officials about the threat to the delicate local ecosystem and to people living there.

The Hong Kong-flagged ship, Solomon Trader, was carrying more than 770 tons of heavy fuel oil when it ran aground last month on Rennell Island, one of the Solomon Islands, which Unesco says is the largest raised coral atoll in the world. The ship is leaking just outside the boundaries of the World Heritage site, called East Rennell.

Officials in Australia, which has a close relationship with the Solomon Islands, said this week that oil had spread along more than three miles of coastline and into the surrounding sea, and that it was approaching the boundaries of the heritage site. The source of the leak has yet to be found.

Australia initially sent experts to help monitor the spill, but Foreign Minister Marise Payne said on Sunday that the country would step up efforts and send equipment, vessels and experts to help contain the damage to Rennell Island, which is home to animal species found nowhere else.

There is a “high risk” that the oil still on the vessel, estimated at more than 650 tons, will leak into the area, Australia’s Department of Foreign Affairs and Trade said on Tuesday. It said the Solomon Islands government had asked for Australia’s help after the ship’s owner and its insurer failed to act.

“Australia has been profoundly disappointed by the slow response of these companies,” the department said.

On Wednesday, the insurer, Korea Protection and Indemnity Club, expressed “deep remorse” on behalf of itself and the vessel’s owner, King Trader, though it said that “matters of liability are yet to be determined.”

In a statement, the insurer said the ship had run aground on Feb. 5 “during an unexpected gale event.” King Trader arranged for a tugboat to remove the vessel, but a cyclone pushed it farther into the reef, damaging the hull and the engine room, according to the statement.

“Inclement weather has made it difficult and at times impossible to access the vessel, and conditions have been too dangerous for external underwater inspections — a key assessment ahead of salvage operations progressing in earnest,” the statement read.

Greenpeace Australia Pacific expressed alarm last week about the spill, calling it a direct threat to Rennell Island and the 2,000 people who live there, and who rely on the ocean and the island’s natural resources for their livelihoods.

“This requires immediate action, compensation and remediation,” Greenpeace said.

Simon Albert, a researcher at the University of Queensland in Australia who has been working with the Solomon Islands government and local communities on Rennell, said the leak was spilling in an “uncontrolled fashion, without any mitigation at all.”

He said the reefs within Kangava Bay, where the oil spill occurred, had the highest live coral cover of the entire island and provided a critical source of food for residents. He said there were “likely to be substantial long-term impacts on the health of the coral reef ecosystems and the communities that depend on them.”

Unesco describes East Rennell, which it designated a World Heritage site in 1998, as a “true natural laboratory for scientific study.” In 2013, the organization put the site on its list of endangered heritage sites, saying it was threatened by commercial logging, overexploitation of its marine resources and the introduction of invasive rats.